An earlier version of Unix for the Macintosh from Apple. Introduced in 1988 and based on AT&T's Unix System V with Berkeley extensions, A/UX was available as an alternative operating system for Macintosh users. Although it included the Macintosh's Finder graphical interface, its main advantage was providing a Unix command line. Lacking on Macintosh computers running the Mac OS at that time, the Unix command line interface offered a host of functions for manipulating text and data (see Unix).

A/UX ran only on Macs with Motorola 68000 CPUs. When Apple switched to PowerPC chips in 1994, it did not port A/UX to the new platform. The last version of A/UX was released a year later.

It Wound Up Unix After All
Starting in 1999, Apple switched its primary operating system for the Macintosh to Mac OS X, which is based on Unix. Like all Unix versions, Mac OS X offers the command line interface as an optional way to direct the computer. See Mac OS X.